MASSIVE ASCITES AND INCONCLUSIVE PERITONEAL CARCINOMATOSIS-LIKE TUMORS AS THE PRESENTING SIGN FOR INTRADUCTAL PROSTATE CARCINOMA. A CASE REPORT.

Abstract

Prostate cancer is a leading health issue for the male population, accounting for 27% of estimated cancer diagnoses in men in 2022 in the USA. The presence of metastatic prostate cancer reduces the five-year survival rate from 99% (in localized prostatic tumors) to just 30%. Peritoneal carcinomatosis from prostate cancer is highly uncommon, with only 18 cases reported. We present a rare case of metastatic prostate cancer to the parietal peritoneum, omentum and terminal ileum, associated with bone metastases. A peritoneal biopsy was performed and ascitic liquid was drawn and sent to cytologic and microbiological analysis, with no definite answer. Although a second and third anatomopathological examinations were performed by different specialists, the result remained inconclusive, suggesting a fibroblastic proliferation of unknown etiology. Further investigations were recommended, following the inconclusive biopsies and uncertainty of the origin of the peritoneal lesions, and an upper GI endoscopy and colonoscopy were performed. After a multidisciplinary tumor board evaluation of the case with consideration of the discrepancies in the histopathological findings and the patient’s status degradation, oncological treatment was initiated, targeting the prostatic cancer and metastatic bone lesions. The patient’s evolution under treatment was favorable, with a progressive reduction of the ascitic fluid, amelioration of the patient’s general status and weight gain. What made our case particular was the difficulty in diagnosing the nature of the peritoneal lesions and the etiology of the recurrent ascites, due to multiple inconclusive histopathological reports, as the peritoneal and intestinal lesions presented an uncommon histopathological aspect for a malignant lesion.